3.8 Tundra and Polar Regions

Home , Polar seas, Ross Sea, West Antarctic Ice Sheet

258 Credit: Andrew Magor/UNEP/Topfoto 259 3.8 Tundra and Polar Regions

f all the terrestrial biomes, tun- permanently frozen subsoil called per- Circle in the Southern Hemisphere (EEA dra is the coldest. Tundra comes mafrost. Because the topsoil is so shallow n.d.). Although similar in many ways, the Ofrom the Finnish word tunturia, and underlaid by permafrost, it becomes two polar regions differ in that the Arctic which means treeless plain (Pullen 1996). quickly saturated with water. Lakes, ponds, is a frozen ocean surrounded by land, There are two distinct types of tundra: the and bogs dot the surface of the Arctic tun- whereas the Antarctic is a frozen continent vast Arctic tundra and high-altitude alpine dra throughout the brief summer months, surrounded by ocean. tundra on mountains. providing moisture for plants and Most of the world’s fresh water is Arctic tundra is located in the Northern nesting and feeding habitats for huge locked up in polar ice caps. Large glaciers Hemisphere on lands encircling the North numbers of waterfowl and other and ice sheets cover Arctic islands and Pole and extending south to the conifer- animals (Pullen 1996). Greenland in the north and the conti- ous boreal forests of the taiga and covering Alpine tundra is found on mountains nent of Antarctica in the south. Where ice approximately 5.6 million km2 (2 million throughout the world, at high altitudes— sheets and glaciers meet the ocean, huge square miles) Wookey 2002). Arctic tundra above the tree line—where conditions are chunks of ice continually break off, in a is characterized by cold, desert-like condi- too cold and too dry for trees to grow. The process known as calving, to give birth to tions. Although somewhat variable from growing season in alpine tundra is approxi- icebergs. Icebergs are found in both Arctic place to place, precipitation on the Arctic mately 180 days. Nighttime temperatures and Antarctic polar oceans. In the north, tundra, including melted snow, is roughly are usually below freezing. Unlike soils in most icebergs are calved from ice sheets 15 to 25 cm (6 to 10 inches) annually. The the Arctic tundra, soils in alpine tundra are along the western coast of Greenland. In average winter temperature is -34° C (-30° usually well-drained (Pullen 1996). Alpine the south, the vast ice sheets and glaciers F); the average summer temperature is 3 to tundra is also characterized by relatively that cover Antarctica give rise to icebergs 12° C (37 to 54° F). Winters are long and high biodiversity. in polar seas. summers brief, with the growing season The Earth’s polar regions are high-lati- The Earth’s tundra and polar regions only 50 to 60 days long. During summer, tude zones above the Arctic Circle in the are unique and vital parts of the global only the top few centimeters of the soil Northern Hemisphere and the Antarctic environment. They are the world’s least thaw. Beneath the surface is a layer of Credit: Brendan C. Fri/UNEP/Topfoto

260 Arctic Region

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� �� brought about by global warming are �� U.K. � �� Den. expected to be greater in tundra and polar �� Ger. �� Map of the Arctic Source: Modified from http://www.lib.utexas.edu/maps/islands_oceans_poles/arctic_region_pol02.jpg regions than for most other places on Earth. In that respect, tundra and polar populated regions. Antarctica has no tion balance by changing average surface regions form a sort of early warning system permanent residents. The Arctic has ap- albedo(albedo is the fraction of sunlight for climate change and its effects on the proximately 3.7 million inhabitants from reflected). During the peak of the last planet and its inhabitants. The monitoring eight countries. Sparsely populated and Ice Age, one-third of the Earth’s land of high-latitude and high-altitude eco- relatively undisturbed, tundra and polar surface was covered by thick sheets of ice systems, then, represents a way to detect regions therefore contain the world’s larg- that extended from polar regions toward early signs of regional and global climate est remaining wilderness areas. They also the equator. The high albedo of these ice change. The advance or retreat of possess a surprising range of natural re- sheets reflected a great deal of sunlight glaciers, ice sheets, and sea ice has been sources, from marine life to oil and gas. Yet out into space, which cooled the Earth given particular attention by climate despite their rugged appearance, tundra and allowed the ice sheets to grow. Large change researchers. and polar regions are fragile ecosystems changes in sea ice extent are also thought A rapid warming trend in the Arctic that are extremely sensitive to the effects to influence deep-ocean convection and polar region over the last 25 years has of resource exploitation. Managing these global ocean currents (Jezek 1995). dramatically reduced the region’s sea ice. regions and their resources effectively Many climate and biogeochemical Scientists have been monitoring ongoing places huge demands on both technical studies indicate that carbon cycling in the changes in Arctic sea ice for decades, both and political capacities (SPRI n.d.). Arctic tundra and boreal forests strongly firsthand through fieldwork and remotely Tundra and polar regions also ex- influences global climate as well. Cold tun- through the use of satellite imagery. In ert a profound effect on global climate. dra soils contain huge amounts of stored 2002, the extent of multi-year Arctic sea Variations in the extent of sea ice, for organic carbon. They are known sinks for ice was the lowest on record since satel-

example, affect the Earth’s surface radia- atmospheric CO2 through the accumula- lite observations began in 1973. There

261 Case Study: Arctic Seas differs above or below the average for the The extent of Arctic sea ice in September– period 1979-2000. The median ice edge the end of the summer melt period–is the for 1979-2000 is indicated by the black most valuable indicator of the state of the outer line. In 2002, total September ice Quite often, a “low” ice year is followed ice cover. On average, sea ice in September extent was 15 per cent below this average. by recovery the next year. However, Sep- covers an area of about seven million km2, This represents a reduction equivalent to tember of 2003 was also extreme, with 12 an area roughtly equal in size to the conti- an area roughly twice the size of Texas or per cent less ice extent than average. Cacu- nent of Australia. Iraq. From caparisons with records prior to lations performed for 30 September 2004 show a sea ice extent loss of 13.4 per cent, In the images above, the Sea Ice Con- the satellite era, this was probably the least especially pronounced north of Alaska and centration Anomaly scale indicates the amount of sea ice that had covered the eastern Siberia. Source: NSIDC per cent by which the local sea ice extent Arctic over the past 50 years.

was only slightly more sea ice present in Researchers also documented tem- America experienced the highest regional 2003. According to one study, perennial perature increases in different regions warming, increasing by 1.06ºC (1.9ºF) per sea ice—sea ice that survives the summer within and near the Arctic Circle, north decade. Greenland cooled by less than and remains year round—is melting at the of 66º. Average temperatures increased one-tenth of a degree C per decade. The alarming rate of 9 per cent per decade by 0.3ºC (0.5ºF) per decade over sea ice cooling found over Greenland was mainly (NASA 2003d). If this trend continues, and by 0.5ºC (0.9ºF) per decade over the at high elevations, while warming trends Arctic sea ice may be gone by the northernmost land areas of Europe and were observed around its periphery. These year 2100. Asia. Temperatures over northern North results are consistent with a National Snow

Pancake ice in the Ross Sea, Antarctica Source: Michael Van Woert/UNEP/NOAA

262 and Ice Data Center study that found dinary. Along the Antarctic Peninsula, for record loss of sea ice around Greenland’s instance, the Wordie Ice Shelf has practi- periphery in 2002 (NSIDC n.d.). cally disappeared. In 2002, a section of the As sea ice melts, Arctic waters warm. Larsen B Ice Shelf collapsed—the largest Less ice means more heat gain by polar wa- such event in the last 30 years. ters, which creates a positive feedback lead- In other parts of Antarctica, however, ing to further ice melting and increased ice cover has actually increased (UPI warming. The loss of Arctic sea ice, and 2003). What is happening with the vast the warming of Arctic polar waters, have West Antarctic ice sheet is not yet clear. Between 2000 and 2002, scientists observed the enormous implications for both regional Some studies seem to indicate that it is get- formation of a crack in the Ward Hunt Ice Shelf on the northern shore of Canada’s Ellesmere and global climate patterns. One major ting thicker (NCPPR n.d.). Other studies Island. The crack allowed the waters of a rare concern is that the disappearance of Arctic indicate that this mammoth ice sheet is freshwater Arctic lake to empty into the Arctic sea ice may cause changes in ocean circula- shrinking in size. If the West Antarctic ice Ocean. Rising temperatures also brought about the thinning of this 3,000-year-old shelf, which tion leading to unexpected and rapid shifts sheet melts, global sea levels would rise by is the Arctic’s largest. Credit: V. Sahanatien/UNEP/Parks in climate worldwide (SPRI n.d.). many metres. Such a change would severe- Canada ly impact densely populated coastal regions Over the past 30 years, Antarctic ice has 2001). Activities in Antarctica are carried around the world, forcing people to move also undergone changes. Ice sheets and out under the Antarctic Treaty, a model of to higher elevations. glacier tongues are among the most dy- international cooperation. In the Arctic, namic and changeable features along the Although the details may be still un- the common needs of indigenous peoples coastal regions of Antarctica. Seaward of a clear, there is no doubt that the Earth’s living in remote areas are addressed line where these masses of ice are ground- tundra and polar regions are undergoing through the Arctic Council and other ed, the ﬂoating ice margins are subject to many changes. Some are related to climate circumpolar institutions. Thus, the polar frequent and large calving events. These change and long-distance pollution. Some regions offer hope that nations can cooper- events lead to annual and decadal changes are the result of on-site human activities. ate in addressing the changes taking places in the position of ice edge varying from On a positive note, many of the human-in- in these and other parts of the several to many kilometres. duced environmental threats in the Arctic world (SPRI n.d). Yet ice events are also occurring in have not yet occurred in the largely un- Antarctica that appear to be out of the or- populated Antarctic (Harrison and Pearce

Case Study: Ninnis Glacier, Antarctica 22 January 2000. This image captures the Nin- 2000 nis Glacier Tongue region soon after the initial To better understand the Antarctic Ice Sheet’s calving. The resultant iceberg (sections A and 2 potential response to global climate change B) had an area of approximately 900 km (347 and its effect on global sea level, it is important square miles). NOTE: Purple dots indicate the to detect and monitor the calving of large ice- area where the iceberg broke away from the bergs. The series of images shown here depect glacier. the 2000 disintegration of the Ninnis Glacier 20 February 2000. At this point Bergs A and tongue into two sections. Each image is a 5 February 2000. Roughly two week after B had almost totally separated, rotated coun- sub-section of a SCANSAR scene of the Ninnis calving, the iceberg split into two sections (A terclockwise, and drifted to the north. Note Glacier Tongue region. and B). When this image was taken Berg A that both sections are now well away from the had drifted 20 km (about 12.5 miles) to the Ninnis Glacier. west, Berg B had drifted to the northeast, and Source: USGS 1999; Schmidt 2000 a smaller section (C) remained grounded in front of the Ninnis Glacier.

263 Case Study: Recession of Gangotri Glacier 1780-2001

Gangotri Glacier is situated in the Uttar Kashi District of Garhwal Himalaya, northern In- dia. With its tributary glaciers, it is one of the largest glaciers in the Himalayas. It has been receding since 1780, although studies show its retreat quickened after 1971. It is currently 30.2 km (18.8 miles) long and between 0.5 and 2.5 km (0.3 and 1.6 miles) wide. The blue contour lines drawn in the image show the recession of the glacier’s terminus over time. They are approximate, especially for the earlier years. Over the last 25 years, Gangotri Glacier has retreated more than 850 m (2 788 ft) with an accelerated recession of 76 m (249 ft) from 1996 to 1999 alone. The retreat is an alarming sign of global warming, which will impact local communities. Glaciers play an important role in storing winter rainfall, regulating water sup- ply through the year, reducing ﬂoods, shaping landforms, and redistributing sediments. Source: NASA 2004j

Credit: NASA 2004

Mountain peak in the Himalayas Credit: Unknown/UNEP/Freefoto.com

264 Huge icebergs are found in Antractica’s regions. the sea levels will rise signiﬁcantly. The study of the sensored remote sensing data are used in monitoring These icebergs inﬂuence the weather and climatic state of icebergs and their behaviors are very impor- the state of icebergs. Credit: Michael Van conditions. It is believed that if these icebergs melt, tant aspects of climae change research. Today, multi- Woert/UNEP/NOAA

Case Study: Drygalski Ice Tongue February 2005 The Drygalski ice tongue is located on the Scott Coast, in the northern McMurdo Sound of Antarctica’s Ross Dependency, 240 km (149 miles) north of Ross Island. It stretches 70 km (43 miles) out to sea from the David Glacier, reaching the sea from a valley in the Prince Albert Mountains of Victoria Land. The ice tongue was discovered in 1902 by Robert Falcon Scott, and is thought to be at least 4 000 years old. This image, collected by the Advanced Synthetic Aperture Radar on the European Space Agency’s ENVISAT satellite, shows the David Glacier on the 1 831-metre-high (6 007- feet-high) Mt. Joyce. As ice piles on the glacier, it slides under its own weight to the ocean. The ice doesn’t break up when it reaches the ocean; rather, it floats, forming a long tongue of ice. The floating end of the David Glacier is the Drygalski Ice Tongue. This floating spit of ice was recently men- aced by the B-15A iceberg, a 120-km-long 22 Feb 2005 (74-mile-long) giant that had been drifting on a collision course with the ice tongue before Credit: European Space Agency—ESA becoming grounded. On 21 February 2005, part of the evolution of the ice tongue—pieces currents, which become more numerous to- Drygalski calved an iceberg. The five-by-ten-km regularly break from the tongue as the glacier wards the end of the tongue. (three-by-six mile) iceberg was floating off the pushes more ice out over the sea. This image Source: NASA 2005, WIKIPEDIA left side of the ice tongue on 22 February when shows cracks, formed by time and ocean this image was acquired. The event is a normal 265 Credit: Olga Tutubalina/UNEP Mount Dzhimarai-Khokh, elevation 4 780 metres (15 682 feet), towers above the Kolka Cirque. Rock and ice falling from the steep walls of the cirque since 13 June 2001 the end of July 2002, eventually triggered the collapse of the Kolka Glacier. NASA Image by Jesse Allen and Robert Simmon based on MODIS data

Case Study: Collapse of the Kolka Glacier of rock and hanging glacier on the north lakes upstream. Boulders, pebbles, and 20 September 2002 face of Mt. Dzhimarai-Khokh tumbled onto mud covered the surface of the debris flow, the Kolka glacier below. Kolka shattered, resulting in treacherous footing. The path- Rebecca Lindsey, Olga Tutubalina, Dmitry setting off a massive avalanche of ice, snow, less maze of debris was only one of many Petrakov, Sergey Chernomorets and rocks that poured into the Genaldon hazards that slowed exploration of the River valley. Hurtling downriver nearly 13 disaster area. Running east to west across the narrow km (8 miles), the avalanche exploded into Scratches on the surface of rocks of the isthmus of land between the Caspian Sea the Karmadon Depression, a small bowl Maili Glacier’s moraine show the violence to the east and the Black Sea to the west, of land between two mountain ridges, and of the event. The avalanche, moving up the Caucasus Mountains make a physical swallowed the village of Nizhniy Karmadon to 180 kilometres per hour (112 mph), barricade between southern Russia to the and several other settlements. scoured the rocks below, leaving parallel north and the countries of Georgia and At the northern end of the depression, grooves called “striations.” Striations are Azerbaijan to the south. In their center, the churning mass of debris reached a typically observed in the bedrock underly- a series of 5 000-metre-plus (16 000-feet- choke point: the Gates of Karmadon, the ing glaciers, created by the slow, scouring plus) summits stretch between two extinct narrow entrance to a steep-walled gorge. action of rocks caught beneath the ice. volcanic giants: Mt. Elbrus at the western Gigantic blocks of ice and rock jammed Large-scale avalanches and glacial col- limit and Mt. Kazbek at the eastern. On the into the narrow slot, and water and mud lapses are not uncommon on the slopes lower slopes, snow disappears in July and sluiced through. Trapped by the blockage, of Mount Kazbek and nearby peaks. The returns again in October. On the summit, avalanche debris crashed like waves against Kolka Glacier collapsed in 1902, surged winter is permanent. Glaciers cover peaks the mountains and then finally cemented in 1969, and collapsed again in 2002. and steep-walled basins into a towering dam of dirty ice and rock, Evidence, including historical accounts, called cirques. The remote, sparsely creating lakes upstream. At least 125 indicates similar events have happened in populated area is popular with tourists people were lost beneath the ice. neighboring valleys as well. and backpackers. The Kolka Glacier collapse partially After the collapse, people speculated Elevations reach 5 642 metres (18 511 filled the Karmadon Depression with ice, that something called a glacial surge had feet), and glaciers accumulate from heavy mud, and rocks, destroying much of the triggered the Kolka collapse. In 1902, a snowfall in the steep mountain valleys. village of Karmadon. The debris swept in more significant collapse at Kolka Glacier Around Mount Kazbek, a dormant volcano, through the Genaldon River Valley and killed 32 people. Despite a history of disas- glaciers intermittently collapse, burying backed up at the entrance to a narrow ters there, routine monitoring of the Kolka the landscape below under rock and ice. gorge. The debris acted as a dam, creating Glacier cirque ended in the late 1980s. The latest of such collapses happened in 2002. Rebecca Lindsey, science writer with 19 October 2002 22 May 2003 11 July 2003 30 August 2003 NASA’s Earth Observatory, in close collabo- ration with Russian scientists Olga Tutubali- na, Dmitry Petrakov (Moscow State Univer- sity), and Sergey Chernomorets (University Centre for Engineering Geodynamics and Monitoring) compiled the details of this event. On the evening of 20 September 2002, in a cirque just west of Mt. Kazbek, chunks

This sequence of images from the Indian Remote Sensing (IRS) satellites showed that the lakes (except Lake Saniba) were draining gradually through crevasses in the ice mass, and were not likely to cause subsequent catastrophic ﬂoods. Credit: IRS

266 Credit: Sergey Chernomorets/UNEP

The rapidly rising water was a continuing a large remnant of the Kolka Glacier, ice fumaroles—volcanic vents—on the face of danger, threatening a sudden outburst that cliffs high above the fl oor of the cirque, Mount Dzhimarai-Khokh in the area where would cause fl ooding downstream. displaced porous ice, the Maili Glacier, a the hanging glacier collapsed. Russian researchers evaluated the risk temporary lake, and deposits of rubble left Based on the available data and obser- of future danger at the disaster site using a along the path of the collapsing glacier. vations, the scientists say they don’t expect time-series of satellite images collected in There is uncertainty also about what any additional catastrophic processes with- the year following the disaster. Satellite im- triggered the collapse of rocks and hang- in the next 10 to 20 years. The remaining agery was crucial throughout the late fall ing glaciers on Mount Dzhimarai-Khokh. lakes will likely continue to drain through and winter of 2002 and 2003, when dan- Two small earthquakes jarred the region in crevasses and channels being cut through gerous weather prevented on-site observa- the months before the collapse, probably the ice mass, and as they drain, the risk of tions of the ice-dammed lakes. destabilized the hanging glaciers. In the fl ooding decreases. Russian scientists combined satellite fi rst days after the collapse, an Emercom data with ground observations to create (Russian Emergencies Ministry) crew fl ew Published 9 September 2004 maps of the Kolka Glacier Cirque. The to the site via helicopter, but was forced to Source: http://earthobservatory.nasa.gov/Study/Kolka/ kolka.html IRS Satellite image (acquired 11 July evacuate immediately when the crew de- 2003) shows details of the cirque, includ- tected an overpowering smell of sulfur-con- ing scars caused by post-collapse rockfall, taining gas. It seems there may be some

Credit: Digital Globe

The area covered by ice and debris dwarfed the hamlet of Karmadon, and the Genaldon River disappeared completely. (The outline corre- sponds to the detailed image above.)

25 Sept 2002 Credit: Olga Tutubalina, Dmitry Petrakov, Sergey Chernomorets/UNEP 267 Case Study: Arctic Sea Ice Evidence continues to emerge that average In September 2003, scientists from the United temperatures in the Arctic are rising even more States and Canada announced that the larg- rapidly than the global average. Satellite data est ice shelf in the Arctic had broken up. The indicate that the rate of surface temperature Ward Hunt ice shelf to the north of Canada’s increase over the last 20 years was eight times Ellesmere Island split into two main parts, with the global average over the last 100 years other large blocks of ice also pulling away from (Comiso 2003). the main sections.

The edge of the pack ice Source: NOAA Source: Michael Van Woert/UNEP/NOAA

268 Credit: Gyde Lund/UNEP

Studies report that the extent of Arctic sea the sea ice, until now thought to be permanent, as access by sea to valuable natural resources ice has shrunk by 7.4 per cent over the past 25 will melt during the summer by the end of this becomes easier. The global impacts may also be years, with record-low coverage in September century if the current trend in global warming signiﬁcant as absorption of solar radiation in- 2002 (Johannessen et al. 2003). An analysis of continues. This will have major direct impacts creases, and could lead to changes in the world 30 years of satellite data suggests that the loss of on indigenous people and Arctic wildlife such ocean circulation (UCL 2003; NASA 2003; Arctic sea ice is also accelerating (Cavalieri et as polar bears and seals, and will also open Laxon et al. 2003). al. 2003). There are projections that much of the region to increased development pressure Source: GEO Year Book 2003

These images reveal dramatic changes in Arctic sea ice since 1979. The loss of Arctic sea ice may be caused by rising Arctic temperatures that result from greenhouse gas build-up in the atmosphere and resulting global warning.

269 During much of the 20th century, Iceland’s Breidam- erkurjökull Glacier has been shrinking. It has been UNDRA studied extensively since 1903, when researchers drew T up detailed maps that showed its base just a few BREIDAMERKURJÖKULL, ICELAND 270 hundred metres from the ocean edge. Over time, the glacier has receded so In this pair of satellite images, notice how the glacier has receded and the that its base is now several kilometers from the coast. As the huge river of glacial lake at its tip has enlarged over time. Some researchers attribute the ice has pulled back across the Icelandic landscape, thousands of hectares of shrinking of Breidamerkurjökull to climate change and global warming. Other fertile farmland have been exposed and people are populating the area that scientists maintain that the glacier is simply retreating from the advance it was until relatively recently buried under tonnes of ice. made during the Little Ice Age.

271 An ice shelf is a huge sheet of ice that is grounded on land but has an extension that UNDRA reaches out into the ocean. Antarctica has two T great ice shelves: the Ross Ice Shelf near the FILCHNER ICE SHELF, ANTARCTICA Ross Sea and the Filchner Ronne Ice Shelf near 272 the Antarctic Peninsula. By volume, the Filchner Ice Shelf is the largest shore. In early 1990, however, A24 broke free and moved out into the ice shelf on the planet. open waters of the Weddell Sea, and finally, in 1991, into the southern In the austral winter of 1986, the front edge of the Filchner Ice Atlantic Ocean. In the 1986 image above, notice how the break line Shelf broke off into the ocean, forming three enormous icebergs created when the icebergs calved has filled with sea ice. Sea ice does named A22, A23, and A24 by glaciologists. Soon after this calving not contain the flow lines that are apparent in the glacial ice of the event, all three icebergs ran aground on the shallow sea floor just off shelf that lies behind the break line. 273 Hubbard Glacier, located at St. Elian National Park near Yakutat, Alaska, is the largest calving UNDRA glacier in North America. It is currently increas- T ing in total mass and advancing across HUBBARD GLACIER, UNITED STATES the entrance of 56-km-long (35-mile-long) Russell Fjord. 274 Credit: Unknown/UNEP/USGS, USFS, Yakutat Range District and National Park Service, Yakutat Ranger Station These photographs show an enlarged eastward-looking view of a small section of the Hubbard Glacier terminus and the evolution of the “squeeze-push” moraine in front of Gilbert Point that blocked the tidal exchange between Disenchantment Bay (bottom of photos) and Russell Fiord (top of photos), creating Rus- sell Lake which rose to 18.6 metres (61 feet) above sea level over 21⁄2 months before it fi nally outburst on 14 August 2002, creating the second largest glacial lake outburst worldwide in historical times.

These images show the potential environmental disruption that a ice dam eventually broke later that year, the water level of Russell fast glacial ﬂ ow is capable of producing. In 1986, the Hubbard Gla- Fjord had risen by 25 m (82 ft). The images show the Hubbard Glacier cier blocked the Russell Fjord, endangering seals and porpoises by and surrounding area at various stages before, during, and after the producing freshwater runoﬀ that reduced the salinity of that body formation of the ice dam. of water. Rising water levels also became a concern. By the time the

275 Credit: Christian Lambrechts/UNEP/UNEP-GRID Nairobi

Mt. Kilimanjaro, Africa’s highest mountain, is located 300 km (186 miles) south of the equator UNDRA in Tanzania. A forest belt that spans between T 1 600 m (5 249 ft) and 3 100 m (10 171 ft) sur- MT. KILIMANJARO, TANZANIA rounds it. The forest has a rich diversity of eco- 276 Credit: Christian Lambrechts/UNEP/UNEP-GRID Nairobi

systems, particularly of vegetation types that result mainly from the alarmingly. An estimated 82 per cent of the icecap that crowned the large range in altitude and rainfall of about 700 to 3 000 mm/yr (28 mountain when it was fi rst thoroughly surveyed in 1912 is now gone, to 118 in/yr). It hosts a very large diversity of species, with about 140 and the remaining ice is thinning as well—by as much as a metre per mammal species and over 900 plant species. But of greater concern year in one area. According to some projections, if recession con- are the glaciers atop the mountain. In 1976, glaciers covered most tinues at the present rate, the majority of the remaining glaciers on of the summit of Mt. Kilimanjaro. By 2000, the glaciers had receded Kilimanjaro could vanish in the next 15 years. 277 Since the discovery of oil in Prudhoe Bay, Alaska, in 1968, the oil industry has dramatically UNDRA transformed the former North American Arctic T wilderness. Prudhoe Bay and 18 other oil fi elds PRUDHOE BAY, UNITED STATES currently sprawl over more than 2 600 km2 278 (1 004 square miles) in the region. North Slope oil fields now include ment plants, and power plants. These satellite images document the 3 893 exploratory and producing wells, 170 production and explor- dramatic changes that the Prudhoe Bay region has undergone over atory drill pads, 800 km (497 miles) of roads, 1 769 km (1 099 miles) the past 35 years. of trunk and feeder pipelines, two refineries, several airports, and a collection of production and gas processing facilities, seawater treat-

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